Pulsed calibration technique of miniature ultrasonic receivers using a wideband laser interferometer

Abstract This Paper describes a new method to calibrate miniature ultrasonic receivers, also called hydrophones. The proposed technique makes use of the particularities of the pulsed ultrasonic field radiated by a planar transducer. The hydrophone sensitivity is deduced from its response to a perfectly characterized transient plane wave. The time shape and the amplitude of the transient pressure is calculated from the ultrasonic displacement measured by a wideband laser interferometer. Thanks to this impulse technique, the hydrophone sensitivity as a function of frequency is obtained after carrying out only one experiment with a single transducer. The choice of this transmitting transducer and of the measurement point are discussed because they play an important part in the validity of the method. The sensitivity of a lead metaniobate hydrophone and a PVDF hydrophone have been measured and the results are in good agreement with those obtained using other calibration techniques.